Sep and lateral pet evidently unlike, the sep linear, elongate, the pet shorter and relatively wider; lip not declined, bearing a prominent median ridge from the base to beyond the middle, 3-lobed, the lateral lobes 2/3 as long as the whole lip, or longer, upturned at the margin, the terminal lobe short, broad, inconspicuously erose; column extending forward over the lip, its terminal anther deflexed; pollinia 2; nectar wanting; perennial from a cluster of fleshy-fibrous roots, the erect glabrous, hollow stem bearing a single whorl of usually 5 lvs near the summit and 1(2) large terminal fl. Only 2 spp.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.